Folder specified already exists.
This error can occur for two reasons:
You are adding a folder to Solution Explorer and the name is already used by another folder.
You are renaming a folder and the name is already used by another folder.
When creating names for folders, use unique names and follow consistent naming conventions using only the allowed characters. For specific rules on valid naming conventions, consult the documentation for your operating system.
To correct this error
Enter a different folder name.
Rename the folder that currently exists and then enter the new folder name.